Systems and methods for adjusting audio levels in a plurality of audio signals

ABSTRACT

Systems and methods for adjusting audio levels in a plurality of audio signals are disclosed. One or more input signals containing one or more audio signals are depacketized. The audio signals are analyzed to determine if audio levels of the signals correspond to a desired audio level for at least some of the signals. The audio levels of signals that do not correspond are adjusted. Packets that do not require adjustment and the resulting adjusted packets are combined to form one or more output signals corresponding to the one or more input signals.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/083,202, filed on Apr. 8, 2011, which is incorporated by referenceherein in its entirety.

FIELD

The described embodiments relate to systems and methods for adjustingthe audio loudness in a plurality of audio signals.

BACKGROUND

Digital audio signals, and digital video signals containing audiosignals, are typically transmitted in data streams according to variousstandards and protocols. A common problem with such audio signals, whichmay also be referred to as audio streams, is a wide variation in theloudness levels of different portions of the audio encoded within theaudio signal. When the audio signal is reproduced as audio, theresulting audible signal has correspondingly large loudness variations.In some situations, portions of an audio signal are intentionallyencoded such that they are reproduced at different audio levels. Inother cases, different portions of the audio signal are producedindependently of one another with the result that they may be encoded toproduce audio at different loudness levels.

Many standards and systems for transmitting audio signals (some embeddedwith a corresponding video signal) allow a plurality of audio signals tobe transmitted within a single transport stream. Each audio signal isdivided into blocks of data, which are then transmitted as a series ofpackets. The packets of the different audio signals are transmittedtogether in the transport stream. In some standards, the different audiosignals may be combined by time multiplexing them such that the audiosignal is divided into different time slices and each audio signal isassigned one of the time slices. In other standards, the packetscorresponding to each signal may be mixed in any order in the transportstream. The packets of each audio signal are tagged with a signalidentifier, allowing them to be combined together to assemble theoriginal audio signal.

In a typical audio or audio-visual data transmission system, sometransport streams may include a plurality of audio signals, each with avarying audio level. It is desirable to analyze and adjust the audiolevels of such audio signals in one or more audio signals such that atleast some of the audio signals may be reproduced with a desirable audiolevel.

SUMMARY

In one aspect, some embodiments provide a system for adjusting the audiolevel of a plurality of audio signals in a transport stream, the systemcomprising: one or more input terminals for receiving the audio signals;an audio signal extraction block coupled to the input terminals toextract packets corresponding to the audio signals; an audio leveladjustment block coupled to the audio signal extraction block to analyzethe audio levels of the audio signals and to provide audio leveladjustment signals corresponding to differences in the audio levels andcorresponding desired audio levels; and an audio signal re-assemblyblock to generate audio adjusted packets corresponding to the audiolevel adjustment signals.

In another aspect, some embodiments provide a method of adjusting theaudio level of a plurality of audio signals, the method comprising:receiving one or more input signals, wherein each input signal includesone or more packetized audio signals; comparing an audio levels of atleast two of the audio signals to a respective desired audio level;adjusting the audio level in packets of at least one of the audiosignals to provide audio adjusted packets; and combining unadjustedpackets and the audio adjusted packets to form one or more outputsignals corresponding to the one or more input signals.

In some embodiments, the audio signals are received in the form of inputsignals containing a plurality of audio signals. One or more of theinputs signals may be transport streams containing packetized inputsignals.

In some embodiments, the audio signal extraction block contains ade-multiplexor for extracting and separating packets corresponding todifferent audio signals from the input signals.

In some embodiments, the audio level adjustment block includes one ormore gain adjustment blocks for comparing the audio levels of some ofthe audio signals to a corresponding desired audio level and forgenerating the audio level adjustment signals corresponding todifferences between the audio levels and the corresponding desired audiolevel.

In some embodiments, some of the audio signals include a gain controlmetadata value and the corresponding audio level adjustment signalsindicates an adjustment in the gain control metadata value. In suchembodiments, the audio level is adjusted by varying the gain controlmetadata value in one or more packets of the audio signal.

In some embodiments, some of the audio level adjustment signals providea modified version of the audio data for one or more packets in theaudio signal, wherein the modified version includes audio data encodedat a modified audio level. The audio level is modified by replacing theaudio data in at least some packet in the audio signal.

In some embodiments, some the audio level adjustment signals indicateboth an adjustment in the gain control metadata value and provide amodified version of the audio data. The audio level for such signals ismodified by both varying the gain control metadata value in one or morepackets in the audio signal and by replacing the audio data in at leastsome of the packets in the audio signal.

In some embodiments a plurality of input signals corresponding eachcontaining a plurality of audio signals is received. In someembodiments, different input signals may be received at different typesof terminals according to different types of data transmission andcommunications standards and protocols.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the invention will now be described withreference to the drawings, in which:

FIG. 1 is a block diagram of an example system for analyzing andadjusting audio levels of a plurality of audio signals;

FIG. 2 illustrates a transport stream containing a plurality of audiosignals;

FIGS. 3 and 4 illustrates other example systems for analyzing andadjusting audio levels of plurality of audio signals.

The drawings are illustrative only and are not drawn to scale. Variouselements of some embodiments may not be shown for clarity. Similar andcorresponding elements of the various embodiments are identified bysimilar reference numerals.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Numerous specific details are set forth in order to provide anunderstanding of the exemplary embodiments described herein. However, itwill be understood by those of ordinary skill in the art that theembodiments described herein may be practiced without these specificdetails or with variation of these specific details. In some instances,well-known methods, procedures and components have not been described indetail so as not to obscure the embodiments described herein.Furthermore, this description is not to be considered as limiting thescope of the embodiments described herein in any way, but rather asmerely describing the structure or operation of several exampleembodiments.

The embodiments of the systems and methods described herein, and theircomponent nodes, devices and operations, may be implemented in hardwareor software, or a combination of both.

Reference is first made to FIG. 1, which illustrates a system 100 foranalyzing and adjusting the audio level of a plurality of audio signalsembedded in respective audio signals. The audio signals are transmittedtogether in a transport stream. System 100 includes an input terminal102, an audio signal extraction block 104, a controller 106, an audiolevel adjustment block 108, an audio signal re-assembly block 110 and anoutput terminal 112.

Reference is additionally made to FIG. 2. An input signal 120 isreceived at input terminal 102. In this example, input signal 120 is atransport stream that includes the plurality of audio signals A, B, C, .. . . Each audio signal encodes a digital audio signal. Each audiosignal has been divided into blocks of data and packetized into a seriesof packets 122 according to the standards used for the audio signal andfor the transport stream.

Each packet 122 includes one or more packet data fields 124 and one ormore audio data fields 128. Some packets 122 also include an audiometadata field 130 in accordance with the respective audio standardsused for each audio signal. Some packets may also optionally includeother data 126 such as video data in accordance with the standards usedfor each audio signal. All such streams and signals are referred toherein as audio streams or audio signals herein, regardless of thepresence or type of other data present in the streams or signals.

The audio data for each audio signal may be extracted from the series ofpackets for that audio signal and may be reassembled to recreate thedigital audio signal encoded in the audio signal. The digital audiosignal may be reproduced using appropriate converting, amplifying andreproduction equipment to generate an audible signal corresponding tothe digital audio signal. For example, a digital audio signal may beconverted into an analog audio signal with a digital-to-analog converter(DAC), which is then amplified by an audio amplifier. The amplifiedanalog audio signal is applied to a speaker or other sound transducer toproduce audible sound.

Some audio signals include audio metadata that may include an audioamplification index that indicates to the converting or amplifyingequipment an audio level at which the digital audio signal is to bereproduced. For example, in Dolby Laboratories™ AC-3 audio compressionsystem, an audio metadata value called Dialnorm is used to controlplayback gain. Other audio compression and encoding systems may provideother mandatory or optional gain control metadata values. Such gaincontrol metadata values are typically intended to be set such thatdialog in a digital audio signal is reproduced at a consistent audiolevel or volume level or sound pressure level from program to programand channel to channel. The gain control metadata value is combined inthe converting or amplifying equipment or both with a listening volumeset by a listener to produce audible sound at an audio levelcorresponding to both the gain control metadata value and the listeningvolume. In practice, different parts of a digital audio signal arefrequently reproduced at widely varying levels often requiring alistener to change the gain of the amplifying equipment to maintain adesired listening volume.

The input signal is received by an extraction block 104 which extractseach packet 122 from the input signal 120. Packets 122 corresponding toeach audio signal are stored within the extraction block 104. Packetscorresponding to each audio signal are sequentially transmitted from theextraction block 104 to adjustment block 108.

Adjustment block 108 analyzes the audio data encoded in each audiosignal. Adjustment block 108 obtains the series of packets for eachaudio signal and, in some embodiments, decodes the audio data from theaudio signal to re-assemble at least a portion of the digital audiosignal. In addition, the audio adjustment block extracts any audio gaincontrol adjustment value in the audio signal. Adjustment block 108analyzes the digital audio signal and any audio gain control adjustmentvalue in the audio signal and determines if the digital audio signal isencoded at an undesirable audio level. If so, the adjustment block 108determines an adjustment for the digital audio signal.

In some embodiments, the adjustment block 108 may sample portions ofsome or all of the audio data encoded in the respective audio signals.The adjustment block may determine adjustments for some or all of theaudio signals based on the respective samples of the audio signals.

In some audio signals, the audio data or audio metadata may include dataindicating the audio level of the audio signal. In such embodiments, theadjustment block may not decode the audio data or reassemble or samplethe audio signal to determine the audio level at which the audio signalwould be reproduced. If such an audio signal also includes a gaincontrol adjustment value, the adjustment block may adjust the gaincontrol adjustment value based on the recorded audio level. For otheraudio signals, the adjustment block may decode the encoded audio signaland then re-encode the audio signal at a different audio level based onthe recorded audio level.

Adjustment block 108 contemporaneously analyzes the audio level of anddetermines an adjustment for each of the audio signals in the inputsignal 122. Typically, the determined adjustment corresponds to thepacketization of each audio signal, such that the audio data or theaudio metadata (or both) in each packet or of a group of packets fromeach audio signal may be adjusted as required such that the audio signalwill be reproduced at a desired audio level. Controller 106 is coupledto adjustment block 108 to provide a desired audio level signal 152 tothe adjustment block corresponding to the desired audio level or adesired audio level range.

The adjustment determined by audio adjustment block is transmitted to anre-assembly block 110. Re-assembly block 110 also receives the inputsignal 120. Re-assembly block 110 modifies at least some of the packetsin the input signal in accordance with the adjustment determined by theaudio adjustment block. The packets 168 are then sequentiallytransmitted to output terminal 112. The digital audio data field 128 orthe audio metadata 130 for the audio signals that require adjustment aremodified in the output signal in accordance with the adjustmentdetermined by the audio adjustment block.

Reference is next made to FIG. 3, which illustrates another system 200for analyzing and adjusting the audio level of a plurality of audiosignals embedded in an audio signal. Elements of system 200corresponding to elements of system 100 are identified by similar orcorresponding reference numerals.

System 200 includes an audio signal extraction block 204, a controller206, an audio level adjustment block 208 and an audio signal re-assemblyblock 210.

Extraction block 204 includes a de-multiplexer 240 and a plurality offirst in-first out (FIFO) buffers 242 a, 242 b, . . . ,242 n. Each FIFObuffer operates in known manner to receive and store data and thenprovide the stored data in the order in which it was received by theFIFO buffer. De-multiplexer 240 is coupled to input terminal 202 fromwhich it receives an input signal 220. Input signal 220 is similar toinput signal 120 (FIG. 1) of system 100. De-multiplexer 240 extractseach of the plurality of audio signals in the input signal 220 andrecords successive packets 222 of each audio signal in one of the FIFObuffers 242 a, 242 b, . . . ,242 n.

Adjustment block 208 includes a decoder 248, and a plurality of gainadjustment blocks 250 a, 250 b. Decoder 248 extracts packets 222 fromthe FIFO buffers 242 a, 242 b, . . . ,242 n. For each audio signal A, B,C, . . . in the input signal 220, the decoder sequentially decodes theaudio data and any audio metadata relevant to the audio level at whichthe encoded audio signal will be reproduced. The decoder transmits theaudio data for each audio signal to one of the gain adjustment blocks250 a, 250 b.

Different types of audio signals may require different types of audiolevel adjustments. Each different type of audio level adjustment may beprovided by a different gain adjustment block 250.

For example, an audio signal with an embedded gain control metadatavalue may be processed by gain adjustment block 250 a that determinesthe audio level of the audio signal. If the audio level does notcorrespond to a desired audio level or audio level range, then the gainadjustment block 250 a determines an adjusted gain control metadatavalue to modify the audio level at which the audio signal will bereproduced as an audible signal. Typically, the desired audio level(which may be an audio level range) for each audio signal is provided bycontroller 206 in the form of a desired audio level signal 252 a. Forexample, if the audio level of the encoded audio signal is higher thanthe desired audio level, the gain control metadata value is adjusted sothat the audio signal will be reproduced at a lower audio level.Conversely, if the audio level of the encoded audio signal is lower thanthe desired audio level, the gain control metadata value is adjusted sothat the audio signal will be reproduced at a high audio level. Gainadjustment block 250 a generates an audio level adjustment signal 258 acorresponding to each packet of each audio signal processed by the gainadjustment block 250 a. The adjustment signals 258 a generated by gainadjustment block 250 a identify the packet to which each adjustmentsignal corresponds and the adjustment required for the gain controlmetadata value in that packet.

An audio signal that does not include an embedded gain control metadatavalue will require a different adjustment. Gain adjustment block 250 bincludes an automatic gain control (AGC) block 254 and an encoder 256.For each audio signal processed by gain adjustment block 250 b, the gainadjustment block 250 b receives a desired audio level signal 252 b fromcontroller 206. The AGC block receives the decoded audio signal for theaudio signal and generates a corresponding adjusted audio signal havingan adjusted audio level corresponding to the desired audio level signalfor that audio signal. The adjusted audio signal is received by encoder256, which encodes the adjusted audio signal in a format suitable forthe audio signal. Gain adjustment block 250 b also generates anadjustment signal 258 b for each packet of each audio signal processedby gain adjustment block 250 b. The adjustment signals generated by gainadjustment block 250 b identify the packet to which each adjustmentsignal corresponds and includes the re-encoded adjusted audio signal forthat packet.

The adjustment block 208 is shared for all audio signals in the inputsignal 220. The individual gain adjustment blocks 250 a, 250 b may betime multiplexed or otherwise shared between different audio signals andwill typically include or have access to data storage elements to recordaudio data and other data for each audio signal, including the desiredaudio level for that signal. In various embodiments, the adjustmentblock may be designed to be scalable such that additional instances of atype of gain adjustment block may be added to allow an increased numberof audio signals to be processed by the adjustment block 208. Similarly,in various embodiments, a plurality of decoders may be provided to allowan increased number of audio signals to be decoded and provided to thegain adjustment blocks.

The gain adjustment blocks 250 a, 250 b generate the audio leveladjustment signals 258 a, 258 b on a packet by packet basis such thatthe adjustment signals can be used to modify the audio level at whichthe audio data in each packet will be ultimately be reproduced. The gainadjustment blocks 250 a, 250 b may determine the audio level adjustmentsignals based on audio content from a plurality of packets in an audiosignal. Typically, a gain adjustment block will analyze audio data froma series of packets in an audio signal to determine the adjustmentrequired for a packet. As a result the adjustment signal 258 a, 258 bfor a particular packet may be determined based on the plurality ofpackets that are sequentially before or after (or both before and after)the particular packet. The gain adjustment blocks may use a variety oftechniques to determine the adjustment required. For example, a gainadjustment block may analyze audio data from moving window of packets inan audio signal. The moving window of packets may correspond to avarious time periods and the length of the window may be varied. In someembodiments, a gain adjustment block may apply various transforms ortechniques to audio data to identify changes that require a faster orslower rate of adjustment in the audio level of the audio signal. Forexample, if a transition from a program portion to an advertisementportion is detected, a gain adjustment block may adjust the audio levelfor the signal more rapidly than during an ongoing program section. Oneexample of a method of adjusting the gain of a signal is described inU.S. Pat. No. 8,275,153, which is incorporated herein by reference.

Audio signal re-assembly block 210 includes a delay block 260 and one ormore audio modification blocks 262 a, 262 b and output signal generationblock 264. Each audio modification block 262 a, 262 b is coupled to oneor more of the gain adjustment blocks 250 a, 250 b and complements theoperation of the coupled gain adjustment blocks.

Re-assembly block 210 receives input signal 220 from the input terminal202. Reassembly block 210 also receives the respective adjustmentsignals 258 a, 258 b generated by the adjustment block 208 correspondingto at least some of the audio signals in the input signal. As inputsignal 220 is processed through the extraction block 204 and theadjustment block 208, the processing takes some time. The input signal220 is received by delay block 260, which buffers the packets 222 ininput signal so that the packets may be adjusted in accordance with thecorresponding adjustment signal 258 a, 258 b.

The operation of each modification block 262 a, 262 b depends on theformat of the packets in the audio signals processed by the modificationblock 262 a, 262 b.

Audio modification block 262 a is coupled to gain adjustment block 250a. Audio modification block 262 a receives packets 222 for one or moreinput signals 220 from delay block 260 and corresponding adjustmentsignals 258 a, 258 b from the coupled gain adjustment block. Theadjustment signals 258 a generated by gain adjustment block 250 aidentify a packet and the adjustment required in the gain controlmetadata value in that packet. For each adjustment signal 258 a, audiomodification block 262 a obtains the corresponding packet 222 from delayblock 260 and modifies the gain control metadata value in the packet,thereby producing an audio adjusted packet 266.

Audio modification block 262 b is coupled to gain adjustment block 250 bfrom which it receives adjustment signals 258 b. The adjustment signalsgenerated by gain adjustment block 250 b identify a packet and includere-encoded audio data for that packet. For each adjustment signal 258 b,audio modification block 262 ba obtains the corresponding packet 222from the delay block 260 and modifies the audio data in the packet,thereby producing an audio adjusted packet 266.

The audio adjusted packets produced by the audio modification blocks aretransmitted to the output signal generation block 264, which combinesthe audio adjusted packets 266 into an output signal 268 at outputterminal 212. Devices (not shown) coupled to output terminal 212 mayreceive the output signal. In this embodiment, the output signal 268 hasthe same format as the input signal 220. For example, in this example,the input signal is a transport stream comprising a series of packets.Output signal 268 is also a transport stream comprising a series ofcorresponding packets in which the audio data, audio metadata or bothhave been adjusted. In this embodiment, the remaining data is notmodified. In this embodiment, and transport stream data is copied fromthe input signal to the output signal, except as may be needed toreflect any changes in the audio data or audio metadata. In this way,the output signal essentially takes the place of the input signal, withonly the audio levels of the various encoded audio signals having beenvaried in accordance with the desired audio levels for each audiosignal. In some embodiments, the output signal may optionally beassembled with packets ordered in the same order as the input signals.

Some packets in an input signal 220 may not be modified and may simplybe duplicated in the corresponding output signal 268. For example, somepackets may correspond to data other than an audio signal. Some packetsin an audio signal or some entire audio signals may not requireadjustment either because the audio signal or at least a portion iswithin the desired audio level criteria or because the particular audiosignal is designated as not to be processed for audio level adjustment.Such packets are obtained by the output signal generation block 264 andadded to the output signal 268.

In other embodiments, the output signal may include additional changesrelative to the input signal. For example, the packet data and otherdata may be modified in some packets.

Reference is next made to FIG. 4, which illustrates another system 300for analyzing and adjusting the audio level of a plurality of audiosignals embedded in an audio signal. Elements of system 300corresponding to elements of systems 100 and 200 are identified bysimilar or corresponding reference numerals.

System 300 has a plurality of input terminals 302 a, 302 b at which aplurality of input signals 320 a, 320 b are received. Each of the inputsignals may be any type of signal or stream that includes packetizedaudio signals, each of which includes audio data corresponding to adigital audio signal. Each audio signal from each input signal isprocessed as described above in relation to system 200. The packets ofeach audio signal are extracted from their respective input signals andstored in a buffer 342 a, 342 b, . . . ,342 n by audio signal extractionblock 304 that includes de-multiplexer 340. The audio level of eachaudio signal is progressively analyzed in audio level adjustment block308. Decoder 348 extracts packets of each audio signal from buffer 342a, 342 b, . . . ,342 n analyzed by gain adjustment blocks 350 a, 350 badapted to analyze the audio signal, depending on its format. The gainadjustment blocks 350 a, 350 b generates audio level adjustment signals358 a, 358 b based on a desired audio level received from controller 306for at least some of the packets in at least some of the audio signals.

Each input signal 320 a, 320 b is coupled to audio signal re-assemblyblock 310. Each input signal is coupled to a delay block 360 whichextracts packets from the input signals and buffers the input signalsfor processing by audio modification blocks 362 a, 362 b, which adjustsindividual packets based on the corresponding audio level adjustmentsignals 358 a, 358 b. The resulting audio adjusted packets 366 arecombined by the output signal generation blocks 364 a, 364 b into anoutput signal 368 a, 368 b at output terminals 312 a, 312 b. One outputsignal is generated for each input signal and the output signal includesa packet corresponding to each packet in the input signal such that theresulting output signal contains the same audio signals as the inputsignal.

In some embodiments, the different input signals 320 a, 320 b may beprocessed by separate audio signal re-assembly blocks 310. In otherembodiments, different input signals may be de-packetized and bufferedseparately, but may then be processed by a shared set of audiomodification blocks 362 a, 362 b. In such embodiments, the audioadjusted packets 366 may be buffered before being combined into therespective output signals 368 a, 368 b. In some embodiments, the delayblock may record a signal identifier unique to each input signal 320 a,320 b with each packet extracted from the input signal. The signalidentifier may then be used to identify the output signal in which thecorresponding audio adjusted packet should be transmitted.

The systems described above allow the audio levels of a plurality ofaudio signals to be adjusted contemporaneously. In some embodiments, oneor more of the audio signals may be adjusted without reassembling oranalyzing all of the audio data corresponding to an audio signal. Forexample, a gain adjustment block may sample periodic portions of theaudio data in an audio signal and may generate an audio level adjustmentsignal based on the sampled portions of the audio signal. In suchembodiments, the audio level adjustment signal may be applied to seriesor plurality of packets in an audio signal to generate audio adjustedpackets.

Various embodiments have been described here by way of example only.Various modification and variations may be made to these exemplaryembodiments without departing from the spirit and scope of theinvention, which is limited only by the following claims.

We claim:
 1. A method of adjusting the audio level of a plurality ofpacketized audio signals in a transport stream, the method comprising:receiving the transport stream comprising a plurality of packetsassociated with the plurality of packetized audio signals; extractingpackets corresponding to each packetized audio signal from the transportstream; for each of at least two packetized audio signals,contemporaneously: analyzing a first subset of packets corresponding tothe packetized audio signal to extract an audio level of the packetizedaudio signal; comparing the audio level to a desired audio level;generating an adjustment signal based on the comparison between theaudio level and the desired audio level; and adjusting a second subsetof packets corresponding to the packetized audio signal according to theadjustment signal to provide audio adjusted packets.
 2. The system ofclaim 1, wherein the first subset of packets is different than thesecond subset of packets.
 3. The method of claim 1, wherein the desiredaudio level is provided as an external signal by an external controllercoupled to the audio level adjustment block.
 4. The method of claim 1,wherein at least some of the plurality of packets comprise an embeddedgain control metadata value.
 5. The method of claim 4, wherein the gaincontrol metadata value is a dialnorm value.
 6. The method of claim 4,wherein adjusting the second subset of packets comprises modifying thegain control metadata value of the second subset of the packets based onthe adjustment signal.
 7. A system for adjusting the audio level of aplurality of packetized audio signals in a transport stream, the systemcomprising: one or more input terminals for receiving the transportstream comprising a plurality of packets associated with the pluralityof packetized audio signals; an audio signal extraction block coupled tothe one or more input terminals to extract packets corresponding to eachpacketized audio signal from the transport stream, the audio signalextraction block further configured to sequentially transmit at leastsome of the packets to an audio level adjustment block; the audio leveladjustment block configured to execute a sequence of steps for at leasttwo packetized audio signals contemporaneously, the steps comprising,for each packetized audio signal: analyzing a first subset of packetscorresponding to the packetized audio signal to extract an audio levelof the packetized audio signal, comparing the audio level of thepacketized audio signal to a desired audio level, and generating anadjustment signal based on the comparison between the audio level andthe desired audio level; and an audio signal re-assembly blockconfigured to adjust a second subset of packets corresponding to thepacketized audio signal comprising the first subset of packets accordingto the adjustment signal to generate audio adjusted packets.
 8. Thesystem of claim 7, wherein the first subset of packets is different thanthe second subset of packets.
 9. The system of claim 7, wherein thedesired audio level is provided as an external signal by an externalcontroller coupled to the audio level adjustment block.
 10. The systemof claim 7, wherein at least some of the plurality of packets comprisean embedded gain control metadata value.
 11. The system of claim 10,wherein the gain control metadata value is a dialnorm value.
 12. Thesystem of claim 10, wherein the audio signal re-assembly block adjuststhe second subset of packets by modifying the gain control metadatavalue of the second subset of the packets based on the adjustmentsignal.
 13. The system of claim 10, wherein the adjustment signalidentifies the corresponding packet and an adjustment required in thegain control metadata value in the packet.